1. Field of the Invention
The present invention relates to a CO2 recovery system and method for achieving energy saving.
2. Description of the Related Art
In recent years the greenhouse effect produced by CO2 has been pointed out as one of causes of the global warming, and a countermeasure against it is urgently required internationally to protect global environment. CO2 is emitted during various human activities, including burning of fossil fuels, and there is an increasing demand to suppress the CO2 emission. Consequently, people have been energetically studying means and methods for suppressing emission of CO2 from power generation facilities such as power plants which use an enormous amount of fossil fuels. One of the methods includes bringing combustion exhaust gas of boilers into contact with an amine-based CO2-absorbing solution. This method allows removal and recovery of CO2 from the combustion exhaust gas. Another method includes storing recovered CO2, i.e., not returning the recovered CO2 to the atmosphere.
Various methods are known for removing and recovering CO2 from combustion exhaust gas using the CO2-absorbing solution. One of the methods includes contacting the combustion exhaust gas with the CO2-absorbing solution in an absorption tower, heating an absorbing solution having absorbed CO2 in a regeneration tower, and releasing CO2, regenerating the absorbing solution, and circulating the absorbing solution recovered to the absorption tower again to be reused. A conventional technique has been disclosed in, for example, Japanese Patent Application Laid-Open No. H7-51537.